Colored Morphing Apparatus for an Electronic Device

ABSTRACT

A user interface ( 200 ) for a portable electronic device ( 100 ) is configured to transition from a first state to a second state to present a plurality of mode-based user actuation targets to a user. The user interface ( 200 ) includes a segmented electro-optical device ( 407 ) configured to open and close shutters, thereby revealing and hiding the user actuation targets. The user interface includes a first polarizer ( 401 ) disposed above the segmented electro-optical device ( 407 ) and a colored reflective polarizer ( 405 ) disposed beneath the segmented electro-optical device. The colored reflective polarizer ( 405 ), which may include a colored dichroic polarizer ( 601 ) and a reflective polarizer ( 602 ), causes the user interface ( 200 ) to exhibit a predetermined color.

BACKGROUND

1. Technical Field

This invention relates generally to a morphing user interface for anelectronic device capable of selectively revealing and hiding one of aplurality of keypad configurations to a user, and more specifically to adevice and method for configuring the light reflective properties ofsuch a morphing user interface.

2. Background Art

Portable electronic devices, such as radiotelephones, are becoming moreand more popular. According to some estimates, over two billion mobiletelephones are in use across the world today. As more people come to usemobile devices, designers and engineers are creating devices thatintegrate more and more features. For instance, many mobile telephonestoday also include digital camera functions and text messagingfunctions. Some even include music playback functions.

One issue associated with the integration of new features andfunctionality with devices like mobile telephones involves the userinterface. Traditional mobile telephones only included twelve to fifteenkeys. These keys included the standard 12-digit telephone keypad, alongwith a “send” key and an “end” key. Such devices are sometimes notcompatible with new features and functions as new modes of operationrequire new, dedicated keys or input devices in addition to the basicphone keys. Further, the devices may also require additional keys forthe purpose of navigation or initiation of the modes within the device.

One solution to the need for more keys in the user interface is tosimply add more buttons to the device. Some devices, for example,include full keypads with forty to fifty keys. The problem with thissolution is that many mobile devices, including mobile telephones, aregetting smaller and thinner. When many keys are clustered in onelocation, the likelihood of user confusion or difficulty with operationof the device increases. What's more, in a particular mode, many of thekeys are not needed. For example, when a device is in a camera mode, thenumber keys 1-9 are generally not needed to take pictures.

Commonly assigned, co-pending U.S. patent application Ser. Nos.11/684,454, filed Mar. 9, 2007, entitled “Multimodal Adaptive UserInterface for a Portable Electronic Device,” and 11/679,228, filed Feb.27, 2007, entitled “Adaptable User Interface and Mechanism for aPortable Electronic Device” each teach a method and apparatus forproviding a portable electronic device that hides and reveals variouskeypad configurations to a user by way of an optical shutter. Theoptical shutter is configured to selectively open and close shuttersegments by the application of an electric field, thereby hiding andrevealing user actuation targets.

One issue with such a solution is that the color of the device, when theoptical shutter is off, is largely dictated by the construction of theof the display system. For example, in on embodiment where standardpolarizers are used about the optical shutter, the color seen when theoptical shutter is closed may be either grey or black. However, somemanufacturers prefer to make their devices fashionable as well asfunctional. Such manufacturers would prefer to be able to specify anoverall device color that is visible by the user.

There is thus a need for an improved morphing display capable ofreflecting a predetermined color.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of an electronic device in accordancewith the invention.

FIG. 2 illustrates an exploded view of one embodiment of a dynamickeypad interface in accordance with the invention.

FIG. 3 illustrates a sectional view of one embodiment of a dynamickeypad interface in accordance with the invention

FIG. 4 illustrates an exploded view of a twisted nematic liquid crystaldisplay in accordance with one embodiment of the invention.

FIG. 5 illustrates a segmented electroluminescent device in accordancewith one embodiment of the invention.

FIG. 6 illustrates one embodiment of a colored dynamic keypad interfacein accordance with embodiments of the invention.

FIG. 7 illustrates an exemplary multimodal device in an OFF or low-powerstate in accordance with one embodiment of the invention.

FIG. 8 illustrates an exemplary multimodal device in a telephone mode inaccordance with one embodiment of the invention.

Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to help toimprove understanding of embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the invention are now described in detail. Referring tothe drawings, like numbers indicate like parts throughout the views. Asused in the description herein and throughout the claims, the followingterms take the meanings explicitly associated herein, unless the contextclearly dictates otherwise: the meaning of “a,” “an,” and “the” includesplural reference, the meaning of “in” includes “in” and “on.” Relationalterms such as first and second, top and bottom, and the like may be usedsolely to distinguish one entity or action from another entity or actionwithout necessarily requiring or implying any actual such relationshipor order between such entities or actions. Also, reference designatorsshown herein in parenthesis indicate components shown in a figure otherthan the one in discussion. For example, talking about a device (10)while discussing figure A would refer to an element, 10, shown in figureother than figure A.

The commonly assigned, copending patent applications, application Ser.Nos. 11/684,454 and 11/679,228, teach an electronic device having amorphing display capable of hiding and revealing various keypadinterfaces. The keypad interfaces each comprise a plurality of useractuation targets. In some embodiments, the keypad configurations areassociated with a particular mode of operation of the device. Further,the user actuation targets presented may be limited to only those neededfor the particular mode of operation, thereby reducing user cognitiveloading.

The morphing keypad performs the hiding and revealing function byopening and closing shutters in an optical shutter element. This opticalshutter element functions as a segmented electro-optical device in thatit selectively alters an axis of polarization of light passing throughthe keypad. When the electro-optical device is used in conjunction withlight polarization layers, the alteration of the axis of polarizationcauses predetermined shutters to “open” or “close”.

Traditional light polarization layers do two things: First, they absorblight polarized along a first axis of polarization. Second, theytransmit light polarized along a second axis of polarization. While somesmall amount of light polarized along the first axis may be reflected,the majority of such light is absorbed by the polarizer. Thesepolarizers are therefore generally grey or black in appearance whenabsorbing light. Thus, in an electronic device as taught in the11/684,454 and 11/679,228 applications, when the user actuation elementsare not present, the face of the device may be black or grey inappearance.

Embodiments of the present invention employ a colored reflectivepolarizer that is configured to reflect a predetermined color of lightpolarized along a first axis, and to absorb other colors. Each “color”,as used herein, is simply a predetermined spectrum of visible light. Forinstance, a “blue” color may be visible light having a wavelength ofbetween 450 and 495 nanometers. The colored reflective polarizer of thepresent invention is configured to reflect the predetermined color andabsorb other wavelengths, thereby causing the morphing display to appeara particular color when either the shutters are closed or the device isoff. The colored reflective polarizer described herein transmits neutrallight polarized along the second axis, similar to traditionalpolarizers.

The colored reflective polarizer is used in conjunction with themorphing display. Turning now to FIG. 1, illustrated therein is portableelectronic device 100 comprising a high-resolution display 101 and asegmented electro-optical display 102. The segmented electro-opticaldisplay 102 is configured as an optical shutter to present a mode-baseddynamic keypad 103 to a user. The mode-based dynamic keypad 103 is oneof a plurality of keypad configurations, and is associated with thecurrent mode of operation of the electronic device 100. The mode-baseddynamic keypad 103, and its keypad configuration, may include only thosekeys necessary for navigating the particular operating mode of thedevice.

In addition to the high-resolution display 101 and the segmentedelectro-optical display 102, the exemplary electronic device 100 shownin FIG. 1 also includes a navigation device 104. The navigation device104 is used for selectively navigating between the various modes of thedevice. The navigation device 104 may also be used as a control for eachoperational mode. The navigation device 104 may be continuallyaccessible to the user. Alternatively, the navigation device may beselectively hidden and revealed by the segmented electro-optical display102. The navigation device 104 is disposed—in the embodiment of FIG.1.—in the keypad region 106 of the electronic device 100. This geometriclocation allows the navigation device 104 to be large and easilyaccessible.

The high-resolution display 101 comprises a liquid crystal display (LCD)configured to present device information to the user. The term“high-resolution display 101” is used herein to refer to a device thatcan present text and images to a user by altering a large number ofpixels which, when viewed collectively by a user, form the presentedtext or image. The term “high resolution” is used herein to mean adisplay suitable for the presentation of text, information, and graphicson a mobile device with sufficient granularity as to be easily switchedbetween graphics or text. For example, the high-resolution display wouldbe one suitable for presenting an image in the Joint PhotographicsExpert Group (JPG) format to the user. Such displays generally areconfigured to turn on and off individual pixels by way of a displaydriver for the presentation of high-resolution information. Examplesinclude a 256-pixel by 128-pixel reflective or backlit LCD. Such displaydevices are manufactured by Samsung and Sony.

The front surface 105 of the electronic device 100 forms the overalluser interface. In the keypad region 106, the segmented electro-opticaldisplay 102 provides a dynamic user input interface. This dynamic userinterface is configured to present different indicators, which mayappear as keys or actuation targets, across the user interface in thekeypad region 106.

Turning now to FIG. 2, illustrated therein is an exploded view of adynamic user interface 200 for a portable electronic device (100) inaccordance with one embodiment of the invention. The user interface 200includes a dynamic keypad region 106 and a display region 201 (thedisplay region 201 is generally atop the high-resolution display 209).The user interface 200 is made from several layers, each layerimplementing a different function. While several layers are shown, itwill be clear to those of ordinary skill in the art having the benefitof this disclosure that each and every layer may not be required for aspecific application. The structure of FIG. 2 is exemplary only.

The user interface 200 of FIG. 2 includes the following components: acover layer 202; a capacitive sensor 203; an optical shutter assembly204; a reflective electroluminescent device 205, a resistive switchlayer 206; a substrate layer 207; and a tactile feedback layer 208.Additionally, a high-resolution display 209 and filler materials 210 maybe included to complete the assembly. While the layers are shownindividually, it will be clear to those of ordinary skill in the arthaving the benefit of this disclosure that some of the various layersmay be combined together. For instance, the cover layer 202 andcapacitive sensor 203 may be integrated together to form a single layer.Similarly, the tactile feedback layer 208 may be integrated into thecover layer 202, and so forth.

Starting from the top with the cover layer 202, a thin film sheet servesas a unitary fascia member for the electronic device (100). A “fascia”is a covering or housing, which may or may not be detachable, for anelectronic device like a mobile telephone. While the drawings hereinemploy a mobile telephone as an exemplary electronic device fordiscussion, it will be clear to those of ordinary skill in the arthaving the benefit of this disclosure that the invention is not solimited. The fascia of the present invention could be used for anyelectronic device having a display and a keypad.

The cover layer 202, in one exemplary embodiment, is a thin, flexiblemembrane. Suitable materials for manufacturing the thin, flexiblemembrane include clear or translucent plastic film, such as 0.4millimeter, clear polycarbonate film. In another embodiment, the coverlayer 202 is manufactured from a thin sheet of reinforced glass. Thecover layer, being continuous and without holes or other apertures orperforations, is well suited to serve as a continuous fascia for theelectronic device (100), keeping dust, debris and liquids from invadingthe device. While the cover layer 202 is continuous, for discussionpurposes, the cover layer 202 will be colloquially sectioned into akeypad region 106 and a display region 201. The keypad region 106 is thesection of the cover layer 202 where user actuation targets, keys, andbuttons will be presented, while the display region 201 is the sectionof the cover layer 202 where the high-resolution display 209 is visible.

Printing may be disposed on the rear face 211. As will be described inmore detail below, in one embodiment of the invention, the coloredreflective polarizer provides color for the front surface (105) of theelectronic device (100). However, even in such an embodiment, selectiveprinting on the cover layer may be desirable. For instance, printing maybe desired around the perimeter of the cover layer 202 to coverelectrical traces connecting the various layers, or electrodes oncertain layers.

Printing may be desired on the front face 213 for various reasons aswell. For example, a subtle textural printing or overlay printing may bedesirable to provide a translucent matte finish atop the electronicdevice (100). Such a finish is useful to prevent cosmetic blemishingfrom sharp objects or fingerprints. By printing only on the rear face211, however, the front face 213 can remain smooth and glossy. Whenprinting is done on the rear face 211 of the cover layer 202, theprinting, being disposed on the inside of the device, is protected fromwear and abrasion. There is generally no printing in the display region201, so the high-resolution display 209 may be easily viewed. Printingabout the display region 201 may be desired, however, for the reasonslisted above.

The cover layer 202 may also include an ultra-violet barrier. Such abarrier is useful both in improving the visibility of thehigh-resolution display 209 and in protecting internal components of theelectronic device (100).

The user interface 200 also includes a capacitive sensor 203. Thecapacitive sensor 203, which is formed by depositing small capacitiveplate electrodes on a substrate, is configured to detect the presence ofan object, such as a user's finger, near to or touching the userinterface 200. Control circuitry detects a change in the capacitance ofa particular plate combination on the capacitive sensor 203. Thecapacitive sensor 203 may be used in a general mode, for instance todetect the general proximate position of an object relative to eitherthe keypad region 106 or the display region 201. The capacitive sensor203 may also be used in a specific mode, where a particular capacitorplate pair may be detected to detect the location of an object alonglength and width of the front surface (105) of the electronic device(100). In this mode, the capacitive sensor 203 may be used to detect theproximate position of an object, such as a user's finger, relative toany of the actuation targets presented.

Turning to the optical shutter assembly 204, this layer includes asegmented electro-optical device configured as an optical shutter. A“segmented” electro-optical display device is used herein to mean adisplay device with less granularity than the high-resolution display(101) referred to above. The segmented electro-optical device is capableof actuating a predefined segment or segments to present a predeterminedtext or symbol graphic to a user, but does not have sufficientgranularity to easily transition from, for example, text to graphics.The term “low resolution” is used herein to differentiate the segmentedelectro-optical device of the optical shutter assembly 204 from thehigh-resolution display 209. While the high resolution display 209 isconfigured to actuate individual pixels to present high resolution textor images, the optical shutter assembly 204 uses electrodes placed atopand beneath the segmented electro-optical device to open and close“windows”, thereby transforming the window from a first, colored stateto a second, translucent state. The optical shutter assembly 204 is“segmented” because individual windows, or shutters, may be controlled.Further, as will be seen in more detail below, by configuring theelectrodes on one side of the segmented electro-optical device, eachshutter can be configured as the alphanumeric indicia, which may includenumbers, letters, or symbols forming images representative of aplurality of actuatable keys. In one embodiment, the alphanumericindicia may comprise graphics corresponding to a twelve-key telephonekeypad.

The optical shutter assembly 204 is configured to present any of aplurality of keypad configurations to a user. Each keypad configuration,in one embodiment, corresponds to a particular mode of operation of theelectronic device (100). For example, a music player mode may correspondto a first keypad configuration, while a phone mode may correspond to analternate configuration. The optical shutter assembly 204 presents eachof the plurality of keypad configurations by transitioning segments ofthe optical shutter assembly 204 from colored states to translucentstates. When translucent, light can pass through each shutter. Whenopaque, a predetermined color is reflected. The result is a reveal andconcealment of each individual key. Each key forms an actuation targetthat can be selected by the user.

A reflective electroluminescent device 205 may be included to provide abacklighting function to the shutters of the optical shutter assembly204. As used herein, “electroluminescent” refers to any device capableof producing luminescence electrically, including light emitting diodes,and equivalent devices. Such a function is useful in improving thevisibility of the keypad region in low-light conditions. In oneembodiment, the reflective electroluminescent device 205 includes alayer of backlight material sandwiched between a transparent substratebearing transparent electrodes on the top and bottom. The electrodes,which may be segmented and patterned to correspond with the shutters ofthe optical shutter assembly 204. One electrode is an actuationelectrode, while another electrode is a ground electrode. Where theelectrodes are segmented, the actuation electrode is generallypatterned. A reflector, integrated into the back of the reflectiveelectroluminescent device 205 allows incident light to be reflected backthrough the display, even when the electroluminescent elements areactive.

The high resolution display 209, which may have its own lighting systemand may also include a polarizing layer 215 configured to polarize lightalong an axis of polarization, may be placed adjacent to the reflectiveelectroluminescent device 205. In one embodiment, the polarizing layer215 is aligned with the colored reflective polarizer such that thetransmission axis of the polarizing layer 215 is aligned with thetransmission axis of the colored reflective polarizer. Further, fillermaterial 210 may be included to complete the assembly.

The resistive switch layer 206 includes a force switch array configuredto detect contact with any of one of the shutters dynamic keypad regionor any of the plurality of actuation targets. An “array” as used hereinrefers to a set of at least one switch. For instance, where the coverlayer 202 is manufactured from glass, one switch may be all that isnecessary. However, when the cover layer 202 is manufactured from thinfilm plastic, multiple switches may be employed. The array of resistiveswitches functions as a force-sensing layer, in that when contact ismade with the front surface (105), changes in impedance of any of theswitches may be detected. The array of switches may be any of resistancesensing switches, membrane switches, force-sensing switches such aspiezoelectric switches, or other equivalent types of technology.

When the cover layer 202 is made from thin plastic film, an array ofswitches may be included on the resistive switch layer to detect theproximate location of a finger actuating one of the keys. Experimentalresults have shown that a deflection of as little as 40 um along thecover layer is sufficient to actuate one of the resistive switches. Whenthe cover layer 202 is made from glass, the capacitive sensor 203 may beused to detect the proximate location, while one or more switches on theresistive switch layer 206 may be used to detect actuation of the rigidcover layer 202. By employing control circuitry to combine this data,the exact shutter actuated may be properly detected.

A substrate layer 207 is provided to carry the various conduits tocontrol circuits and drivers for the layers of the display. Thesubstrate layer 207, which may be either a rigid layer such as FR4printed wiring board or a flexible layer such as copper traces printedon a flexible material such as Kapton®, includes electrical connectionsto components, integrated circuits, processors, and associated circuitryto control the operation of the display. The substrate layer 207includes a connector 214 for coupling to other electrical componentswithin the electronic device (100).

As noted in the discussion of the resistive switch layer 206 above, inone embodiment a modicum of deflection is all that is required toactuate one of the keys presented by the optical shutter assembly 204.Where the cover layer 202 is manufactured from thin film plastic, aminor deflection of the plastic will actuate a switch on the resistiveswitch layer 206. Where the cover layer 202 is manufactured from glass,a minor deflection of the entire cover layer 202 will actuate a switchon the resistive switch layer 206. This deflection is on the order oftens of micrometers. As such, a user may not perceive any deflection atall when pressing each key.

To provide tactile feedback, an optional tactile feedback layer 208 maybe included. The tactile feedback layer 208 may include a transducerconfigured to provide a sensory feedback when a switch on the resistiveswitch layer detects actuation of a key. In one embodiment, thetransducer is a piezoelectric transducer configured to apply amechanical “pop” to the user interface 200 that is strong enough to bedetected by the user. Thus, the tactile feedback layer provides sensoryfeedback to the user, thereby making the smooth, substantially planaruser interface 200 react like a conventional keypad without the need ofindividual popple-enabled keys protruding through the keypad.

Turning now to FIG. 3, illustrated therein is a side view of the userinterface (200) shown in FIG. 2. Each layer may be seen from the side ina cut-away view. Again, it will be clear to those of ordinary skill inthe art having the benefit of this disclosure that the invention is notlimited to the specific structure shown in FIG. 3. Some layers, as notedabove, are optional and may not be included in certain applications.

Note that the layers may be coupled together in any of a variety ofways. One exemplary embodiment of a coupling mechanism is by using athin layer of clear (transparent), non-conductive adhesive. Forinstance, the cover layer 202, the capacitive sensor 203, and theoptical shutter assembly 204 may each be mechanically coupled togetherwith non-conductive, translucent adhesive. This coupling keeps theoverall assembly properly aligned within the device.

When viewing from the top, a user first sees the cover layer 202, whichmay be either a thin film plastic or glass layer. Where glass is used,reinforced glass is often preferred to provide additional reliability tothe user interface (200). The glass may be reinforced by a strengtheningprocess, such as a chemical or heat treatment process. As noted above,the cover layer may include printing disposed thereon.

Next, the capacitive sensor 203 may be seen. The capacitive sensor 203includes both an electrode layer 301 and substrate layer 302. Thesubstrate layer 302, which may be either rigid, or soft (for instance asilicone layer), carries the electrode plates that form the capacitivesensors. The electrodes may be used in a singular configuration, or inpairs. Further alternate electrode pairs, including electrode groupingsof two, four, or six electrodes, may be used to form the capacitivesensors. The electrode layer 301, as will be described in more detailbelow, may be formed by printing solid indium-tin oxide (In.sub.2O.sub.3 SnO.sub.2) (ITO) in the desired capacitor plate patterns atopthe substrate layer 302. Other materials, including patterned conductiveinks, may also utilized in the electrode construction.

Next, the optical shutter assembly 204 may be seen. In one embodiment,the segmented electro-optical device of the optical shutter assembly 204is manufactured using a twisted nematic liquid crystal display material.This material will be discussed herein as an exemplary embodiment.However, it will be clear to those of ordinary skill in the art havingthe benefit of this disclosure that the invention is not so limited.Other materials, including polymer-dispersed liquid crystal material,super twisted nematic liquid crystal material, ferro-electric liquidcrystal material, electrically-controlled birefringent material,optically-compensated bend mode material, guest-host materials, andother types of light modulating may equally be used.

The optical shutter assembly 204 includes twisted nematic liquid crystaldisplay material 303 that is sandwiched between two electrodes 304,305and two substrates 306,307. The electrodes 304,305 and substrates306,307 are preferably transparent, such that light can pass freelythrough each. The substrates 306,307 may be manufactured from eitherplastic or glass. The upper electrode 304 is constructed, in oneembodiment using indium-tin oxide affixed to substrate 306. The lowerelectrode 305 is constructed using a patterned indium-tin oxide layeraffixed to the lower substrate 307. In one embodiment, the patterns arethose of alphanumeric keys or symbols representing keys or useractuation targets of the device. Where it suits the particular design orapplication, both electrodes 304,305 can be patterned; however, uservisibility may be affected where both electrodes 304,305 are patterned.The patterned electrode(s) 305, by way of patterned electrical traces,is connected to a control circuit 308. The control circuit 308 applies afield to the patterned electrode(s) 305, while the other electrode 304acts as a ground. The direction of the electric field is not importantto the optical shutter assembly 204, thus either electrode can act asthe ground.

The electric field applied, as will be described in more detail below,alters the light transmission properties of the twisted nematic liquidcrystal display material 303. The electric field can cause sectionsunder each of the patterned electrodes 305 to transition from a firststate to a second state. By way of example, the first state may beopaque, while the second state is translucent. The patterns of thepatterned electrodes 305 define the images of each shutter in theoptical shutter. By way of example, a shutter can be patterned as a “9key” for a phone by patterning one electrode as a box (i.e. the boundaryof the key), and another electrode as the “9 wxyz” characters. Theshutters thus act as “windows” that can be open or closed, to reveal orhide images.

The optical shutter assembly 204, as will be described in more detailbelow, also includes multiple polarizing layers disposed atop andbeneath the optical shutter. These polarizing layers, which include thecolored reflective polarizer, polarize light along a polarization axisand provide a predetermined color to the overall display assembly.

The reflective electroluminescent device 205 includes a layer ofelectroluminescent material 309 sandwiched between a transparentsubstrate 310 bearing a single, or patterned, indium tin oxideelectrode(s) 311 and a ground electrode 312. In one embodiment, thepatterned electrode 311 of the reflective electroluminescent device 205is aligned with the various shutters of the optical shutter assembly204. In such an embodiment, the ground electrode 312 may comprise asolid conductive ink layer printed on the bottom surface of theelectroluminescent material 309. This solid conductive ink layer mayhave reflective properties. Alternatively, the reflectiveelectroluminescent device 205 may have a reflective layer integratedbeneath the ground electrode 312. Also, the ground electrode 312 may bepatterned and may be borne on a reflective substrate if desired. Oneelectrode layer 301 is connected to control circuitry 308. Like theoptical shutter assembly 204, either electrode layer 311,312 can act asthe ground.

In one embodiment, the high-resolution display 209 is disposed at leastpartially under the optical shutter assembly 204. In such an embodiment,the optical shutter assembly 204 passes beneath the display region(201), thereby covering at least a portion of the high-resolutiondisplay 209. Thus, when a shutter above the high-resolution display 209closes, the high-resolution display 209 is completely hidden. Thisaction gives the overall device (100) a “blank” face of a predeterminedcolor when the electronic device (100) is OFF. Beneath the reflectiveelectroluminescent device 205 are the resistive switch layer 206, thesubstrate layer 207, and the tactile feedback layer 208 with itstransducer 315.

Turning now to FIG. 4, illustrated therein is an exploded view of anoptical shutter assembly 204 for a portable electronic device (100) inaccordance with the invention. The optical shutter assembly 204 of FIG.4 is configured to selectively present one of a plurality of keypadconfigurations to a user.

The optical shutter assembly 204, in one embodiment, employs atwisted-nematic liquid crystal segmented electro-optical device 407.This segmented electro-optical device 407 is referred to as “twisted”because it contains liquid crystal elements that twist and untwist indiffering amounts to alter the polarization of light passing through.

A first polarizer 401 is disposed on a first side of the segmentedelectro-optical device 407. The first polarizer 401 is configured topolarize incident light along an axis of polarization. Stateddifferently, light polarized along one axis passes through the firstpolarizer 401, while light polarized along a second axis is absorbed.

The segmented electro-optical device 407 includes a pair of substrates.A first substrate 402, having indium tin oxide electrodes (as previouslydiscussed) printed in varying shapes is disposed adjacent to the firstpolarizer 401. The electrodes may be disposed in shapes that correspondto the alphanumeric keys or symbols associated with the keys of theelectronic device (100).

Twisted nematic liquid crystal material 403 is next, followed by anothersubstrate 404 configured with ground electrodes. Where no voltage isapplied to the electrodes, the optical shutter assembly 204 is in afirst state. When voltage is applied the liquid crystal materialtwists—in incremental amounts up to 90 degrees—thereby changing theluminous polarization of light passing through the twisted nematicliquid crystal material 403. The twisted nematic liquid crystal material403 thus acts as a controllable polarizer, controlled by electricalsignals applied to the electrodes. Adjustment of the voltage beingapplied to the electrodes permits varying levels polarization axisrotation. Embodiments of the present invention use this device as alow-resolution display to reveal and hide keys.

A colored reflective polarizer 405 is disposed on a second side of thesegmented electro-optical device 407, opposite the first polarizer 401.The colored reflective polarizer 405 is configured to reflect apredetermined color of light polarized along a first axis, and totransmit light polarized along a second axis. In one embodiment, thecolored reflective polarizer 405 is made of two layers: a coloreddichroic polarizer layer and a reflective polarizer layer. The coloreddichroic polarizer is configured to absorb light of a certain wavelengthrange polarized along a first axis, while passing through light of acertain wavelength range polarized along that axis. The colored dichroicpolarizer is also configured transmit light polarized along a secondaxis.

By way of example, consider light polarized along a first axis, P1, andlight polarized along a second axis, P2. The colored dichroic polarizermay will absorb most P1 light, while still passing a certain wavelengthrange—or color—through. All light polarized along the second axis, P2,will pass through the colored dichroic polarizer. When the segmentedelectro-optical device 407 is used with the colored reflective polarizer405 in accordance with embodiments of the invention, the “twisting” ofthe segmented electro-optical device 407 is used to facilitate thereflection of predetermined color from the colored reflective polarizer405. In so doing, the colored dichroic polarizer “looks” a predeterminedcolor to the user. The reflective polarizer is configured to reflectlight polarized along a first axis and to transmit light polarized alonga second axis.

A second polarizer 406 is disposed adjacent to the colored reflectivepolarizer 405 and opposite the segmented electro-optical device 407. Thesecond polarizer 406 operates in similar fashion to the first polarizer401, in that light polarized along one axis is absorbed while lightpolarized along another axis passes through. In one embodiment, thesecond polarizer 406 has a polarization transmission axis that issubstantially orthogonal with a transmission axis of the first polarizer401.

Turning now to FIG. 5, illustrated therein is one embodiment of areflective electroluminescent device 205, or reflective light source, inaccordance with embodiments of the invention. The reflectiveelectroluminescent device 205 includes patterned electrodes 501 that arepositioned to correspond to the shutters of the optical shutter assembly(204). By using patterned electrodes 501, light segments may beselectively actuated. In other words, when the each shutter is actuatedto transition from an opaque state to a translucent state, acorresponding patterned electrode, and thus a correspondingelectroluminescent cell, is actuated so as to project light through theactuated segment. By actuating selective patterned electrodes 501, onlythose corresponding to open shutters are actuated, thereby reducingoverall power consumption of the electronic device (100).

The reflective electroluminescent device 205 may also include areflective layer 502 coupled thereto. For instance, the reflective layer502 may be disposed beneath the electroluminescent device.Alternatively, the reflective layer 502 may be integrated within theelectroluminescent device.

Turning to FIG. 6, illustrated therein is the operation of an opticalshutter assembly (204) in accordance with embodiments of the invention.Two cases 603,604 are illustrated in FIG. 6. The first case, case 603,is where the segmented electro-optical device 407 has segments “open”.Case 604 is where no segments of the segmented electro-optical device407 are open.

Beginning with case 603, incident light 605 is represented as having acomponent of light 607 polarized along a first axis, P1, and a componentof light 609 polarized along a second axis, P2. The first polarizer 401is configured to absorb light polarized along axis P2, and to pass lightpolarized along P1. Thus, light 609 is absorbed at point 611, whilelight 607 passes through the first polarizer 401.

Segment 615 of the segmented electro-optical device 407 is open. Thismeans that the segmented electro-optical device 407 causes thepolarization axis of incident light to rotate. In one embodiment, thisrotation is 90 degrees. Thus, incident light 607, polarized along axisP1, becomes light 613, polarized along axis P2, upon leaving thesegmented electro-optical device 407.

The colored reflective polarizer 405, shown in FIG. 6 comprising acolored dichroic polarizer 601 and a reflective polarizer 602, isconfigured to pass light polarized along one axis of polarization. Asthis transmission axis of the colored dichroic polarizer 601 issubstantially orthogonal with that of the first polarizer 401, light 613passes through the colored dichroic polarizer 601. Similarly, light 613passes through the reflective polarizer 602.

When light 613 reaches the reflective electroluminescent device 205, itis reflected at point 617 off of the reflective component of thereflective electroluminescent device 205. The reflected light 619,having the same polarization P2, then passes back through all thelayers, rotating as it passes through the segmented electro-opticallayer 407. Similarly, light 623 originating at the reflectiveelectroluminescent device 205, which may have both P1 and P2 components,passes through the reflective polarizer with polarization P2. This lightthen is able to pass through the other layers in a manner similar tothat of light 619.

Turning to case 604, the presentation of a predetermined color may bemore clearly illustrated. As with case 603, incident light 606 isrepresented as having a component of light 608 polarized along a firstaxis, P1, and a component of light 610 polarized along a second axis,P2. As noted with case 603, the first polarizer 401 is configured toabsorb light polarized along axis P2, and to pass light polarized alongP1. Thus, light 610 is absorbed at point 612, while light 608 passesthrough the first polarizer 401.

In case 604, the applicable segment 614 is in the “closed” state. Assuch, light 608 passes through the segment 614 without any polarizationrotation. For the purposes of discussion, light 608 is illustrated ashaving three color components, red, green, and blue. The red componentis represented by light 616, the green component by light 618, and theblue component by light 620. These components combine to make “white”light. The components are illustrated separately in FIG. 6 to illustratethe operation of the colored reflective polarizer 405.

The colored reflective polarizer 405 operates as a polarizationdependent reflective layer in that it is configured to transmit only acolor of light of a first polarization (absorbing other colors), and totransmit all colors of light of a second polarization. Looking moreparticularly at the colored dichroic polarizer 601, the colored dichroicpolarizer 601 is a polarizer configured to absorb light polarized in apredetermined direction and predetermined visible range of wavelength.Light polarized in a direction different from the predetermineddirection transmits through the colored dichroic polarizer 601. Thecolored dichroic polarizer 601 also transmits light with wavelengthoutside of the predetermined visible range.

Thus, presuming for discussion purposes that the colored dichroicpolarizer 601 is a “green” polarizer, light 616 will be absorbed atpoint 622. Similarly, light 620 will be absorbed at point 624. Light618, the green component, will pass through the colored dichroicpolarizer.

The reflective polarizer 602 reflects light polarized in a firstdirection and transmits light polarized in a second direction. The firstand the second direction are essentially orthogonal to each other. Incase 603, it was seen that light 613, polarized along axis P2,transmitted through the reflective polarizer 602. In case 604, light618, the green component polarized along P1, reflects off the reflectivepolarizer 602 at point 626 as light 628. Since light 628 has the same P1polarization, it passes through the colored dichroic polarizer 601, thesegmented electro-optical device 407 and the first polarizer 401.

The user sees light 628 as the color green, thereby making the overalldevice look green. Thus, as illustrated, in case 604, representing afirst state, the user interface of the device is configured to reflect apredetermined color by way of a polarization dependent reflectorconfigured to reflect a predetermined polarization of incident lightwhen in the first state. When the device is in a second state,represented by case 603, the user interface presents one of a pluralityof mode based keys by selectively actuating the shutters of theelectro-optical device. The device may transition between the first andsecond states, by way of example, when the capacitive sensor orproximity detector detects an object within a predetermined distance ofthe device.

Recall from the above that in one embodiment, the segmentedelectro-optical device 407 spans not only the keypad region (106), butthe high-resolution display (209) as well. In such an embodiment, whenthe device is active, a shutter above the high-resolution display (209)opens so that the user may view the high-resolution display (209). Insuch an embodiment, when the device is in the first state, the userinterface appears blank and has a color corresponding to theconfiguration of the colored dichroic polarizer 601. In the secondstate, both user actuation targets and the high resolution display (209)become visible.

Turning now to FIG. 7, illustrated therein is an electronic device 700employing a user interface in accordance with embodiments of theinvention. The electronic device is in the first state, which may be anOFF or low-power mode. When the segmented electro-optical device 407covers both the keypad region (106) and the high-resolution display(209), the dynamic user interface surface 702 of the electronic device700 will be blank and have a predetermined color. This occurs becauseeach of the shutters is closed, thereby causing a predetermined color oflight to pass through the colored dichroic polarizer (601) and toreflect off the reflective polarizer (602).

Turning now to FIG. 8, illustrated therein is the electronic device 700having changed from the OFF state (or alternatively the low power state)to an ON state. The ON state may be one of any of a variety of modes,including a radiotelephone mode, a navigational mode, a gaming mode, amusic player mode, a video player mode, a picture display mode, a textcapture mode, a picture capture mode, or a video capture mode. Theelectronic device 700 may be converted from the OFF or low power mode toan ON mode in one of a variety of ways. A first method, as noted above,is for a user to actuate the proximity sensor. A second method is froman external event, such as an incoming call or message. Whentransitioning from the OFF state or low power state to the ON state, theelectronic device 700 opens at least one display segment of thesegmented optical shutter device 801, thereby transitioning that segmentfrom a predetermined color to the translucent state.

In the ON state, light 619 originates from the reflectiveelectroluminescent device (205) and passes through the segment 801.Similarly, incident light may be reflected from the reflectiveelectroluminescent device (205) through the segment 801. Other portionsof the device, such as region 803, may still reflect the predeterminedcolor 805. The high-resolution display 209 may also become visible.

As illustrated and described, embodiments of the invention include auser interface for receiving touch input. In one embodiment, the userinterface includes a first polarizer cover layer and a liquid crystalsegmented electro-optical layer. The liquid crystal material is disposedbetween a first and second substrate, and is configured to selectivelyalter a polarization of light transmitted therethrough. Transparentelectrodes disposed on one of the substrates are configured toselectively present one of a plurality of keypad configurations to auser.

A colored reflective polarizer, operating as a polarization dependentreflective layer, is disposed beneath the segmented electro-opticallayer. The colored reflective polarizer is configured to reflect a colorof light of a first polarization and to transmit light of a secondpolarization.

In the foregoing specification, specific embodiments of the presentinvention have been described. However, one of ordinary skill in the artappreciates that various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theclaims below. Thus, while preferred embodiments of the invention havebeen illustrated and described, it is clear that the invention is not solimited. Numerous modifications, changes, variations, substitutions, andequivalents will occur to those skilled in the art without departingfrom the spirit and scope of the present invention as defined by thefollowing claims. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofpresent invention.

1. A optical shutter assembly for a portable device configured to selectively present one of a plurality of keypad configurations to a user, the optical shutter assembly comprising: a segmented electro-optical device; a first polarizer disposed on a first side of the segmented electro-optical device; and a colored reflective polarizer disposed on a second side of the segmented electro-optical device; wherein the colored reflective polarizer is configured to reflect a predetermined color of light polarized along a first axis, and to transmit light polarized along a second axis.
 2. The optical shutter assembly of claim 1, further comprising a second polarizer disposed adjacent to the colored reflective polarizer and opposite the segmented electro-optical device, the second polarizer having a second polarizer transmission axis substantially aligned with a transmission axis of the first polarizer.
 3. The optical shutter assembly of claim 1, further comprising a reflective light source disposed beneath the segmented electro-optical device, wherein the reflective light source is configured to project light through a segment of the segmented electro-optical device when the segment is in a translucent state.
 4. The optical shutter assembly of claim 3, wherein reflective light source comprises an electroluminescent device and a reflector configured to reflect incident light.
 5. The optical shutter assembly of claim 1, wherein the colored reflective polarizer comprises a colored dichroic polarizer configured to absorb light polarized along the first axis and to transmit light polarized along the second axis coupled to the segmented electro-optical device, and a reflective polarizer configured to reflect light polarized along the first axis and to transmit light polarized along the second axis coupled to the colored dichroic polarizer.
 6. The optical shutter assembly of claim 1, wherein the segmented electro-optical device comprises a twisted nematic liquid crystal display configured to, in a first state, facilitate a reflection of the predetermined color from the colored reflective polarizer.
 7. The optical shutter assembly of claim 1, wherein the segmented electro-optical device is configured to present the one of the plurality of keypad configurations by transitioning segments in a keypad region of the segmented electro-optical device from a state reflecting the predetermined color to a translucent state.
 8. The optical shutter assembly of claim 7, further comprising a high-resolution display disposed beneath the optical shutter assembly in an area other than the keypad region.
 9. The optical shutter assembly of claim 8, wherein the high-resolution display comprises a backlit liquid crystal display configured project light having an axis of polarization substantially aligned with the second axis.
 10. The optical shutter assembly of claim 7, wherein the segmented electro-optical device comprises translucent electrodes coupled thereto and configured as predetermined segments, wherein the predetermined segments geometrically comprise at least a twelve-character telephone keypad.
 11. A multimodal device comprising a dynamic user interface surface configured to reflect a predetermined color by way of a polarization dependent reflector configured to reflect a predetermined polarization of incident light when in a first state, and when in a second state to present one of a plurality of mode based keys to a user by selective actuation of an optical shutter device.
 12. The multimodal device of claim 11, further comprising a capacitive sensor configured to detect proximity of an object within a predetermined distance of the multimodal device, wherein at least a portion of the dynamic user interface surface is configured to transition from the first state to the second state upon the capacitive sensor detecting the object.
 13. The multimodal device of claim 11, further comprising a high resolution display disposed beneath the dynamic user interface surface, wherein the high resolution display is visible only when the multimodal device is in the second state.
 14. The multimodal device of claim 11, wherein the one of the plurality of mode based keys comprise alphanumeric keys, a predetermined symbol keys, or combinations thereof.
 15. The multimodal device of claim 11, wherein the plurality of mode based keys corresponds to a plurality of modes of operation of the multimodal device, wherein the plurality of modes of operation comprises one of a radiotelephone mode, a navigational mode, a gaming mode, a music player mode, a video player mode, a picture display mode, a text capture mode, a picture capture mode, or a video capture mode.
 16. A electronic device having a user interface for receiving a touch input, the user interface comprising: a first polarizer cover layer; a liquid crystal layer disposed beneath the first polarizer cover layer and between a first and second substrate to selectively alter a polarization of light transmitted therethrough; a polarization dependent reflective layer disposed beneath the liquid crystal layer and configured to reflect a color of light of a first polarization and to transmit light of a second polarization; and transparent electrodes disposed on one of the first or second substrate configured to present one of a plurality of keypad configurations to a user.
 17. The electronic device of claim 16, further comprising an electroluminescent device having a plurality of selectively lightable segments configured to align with the transparent electrodes.
 18. The electronic device of claim 16, wherein the transparent electrodes comprise selectively actuatable segments configured to create a plurality of user actuation targets by transitioning from a first state to a second state.
 19. The electronic device of claim 18, further comprising a proximity detector configured to actuate the transparent electrodes.
 20. The multimodal device of claim 15, wherein the multimodal device comprises a radiotelephone. 